The present invention relates to a technology for maintaining the temperature of a fuel cell system that operates intermittently.
In a fuel cell system, because electric power is generated by the chemical reaction between hydrogen and oxygen, water is generated during electric power generation. When the fuel cell system operation is stopped and the temperature of the fuel cell system falls below the freezing temperature, the water remaining in the fuel cell system freezes, thereby potentially blocking the hydrogen and air supply paths and causing freezing of the electrolyte membrane.
In a moving object in which the fuel cell system is installed, such as a vehicle, because the fuel cell system operates intermittently, when operation of the fuel cell system is stopped, the temperature of the fuel cell system may fall below the temperature at which water freezes. Accordingly, in a moving object, during a suspension of an operation of the fuel cell system, a temperature-maintenance operation of the fuel cell system is carried out in order to maintain the temperature of the fuel cell system at a temperature higher than the freezing temperature of water.
However, because the fuel cell continues to generate power when the temperature-maintenance operation is underway, power can continue to be supplied to the generator that outputs the drive power for the moving object, which may cause the moving object to move.